when forced thermal state with radeon.dpm=1
with these changes:
XXX: gist doesn't exist online anymore 7dec98c4c961806550a9#file-zee-patch-L95-L167
then, the system will crash on boot after "Loading initial ramdisk..."
and must power down from the button (4 sec)

this might mean that when card was already overheating, booting kernel will crash

ok, apparently it's working now (with zee2.patch although yesterday I didn't think so) however the voltage is 988 instead of 888
like so:
sclk: 20000 vddc: 988

but when adding the ability to set to thermal via 
 echo '1' > /sys/class/drm/card0/device/power_dpm_state
(zee3.patch)
and turning off that always thermal mode (which sets 988 vddc)
then it works correctly after echoing 1
sclk: 20000 vddc: 888

ok, zee4.patch  allows
 echo 'thermal' > /sys/class/drm/card0/device/power_dpm_state
but cat-ing it still reports 'performance'
maybe it would report thermal if that bool were set: rdev->pm.dpm.thermal_active

